In view of actual application, one or more types of the universal interfaces, such as Ethernet/UART (Universal Asynchronous Receiver/Transmitter)/HDLC (High-Level Data Link Control)/I2C (Inter Integrated Circuit)/SPI (Serial Peripheral Interface), are configured in lots of embedded systems, while network interfaces are not configured in some application environments in view of cost and miniaturization.
There are higher demands on the low cost, miniaturization and low power consumption of a communication device with the continual maturity of IT technology and daily fierce competition. The simplification of up and down service interface need to be considered, and some unnecessary hardware need to be discarded during the product global design. For example, with regard to ordinary single board, the requirement may be satisfied simply by preserving parallel interfaces for debugging without any network interfaces, thus, not only the hardware cost can be reduced, but also the wiring can be reduced and the size of printed board can be reduced. However, the network interfaces may offer more services of application layer, e.g. FTP (File Transfer Protocol)/HTTP (Hypertext Transfer Protocol)/TELNET (TCP/IP terminal emulation protocol)/NFS (Net File System) compared to series interfaces, these application services could not by applied without configuring the network interfaces.